A four-period study to evaluate if the grade glucose infusion procedure will be able to detect an increase in beta-cell glucose sensitivity from exenatide compared to no treatment in healthy subjects.

Inclusion Criteria:

• Subject is in good health
• Subject is a non-smoker

Exclusion Criteria:

• Subject has irritable bowel disease
• Subject has a history of cancer
• Subject has a history of hypertension requiring treatment
• Subject is unable to refrain from the use of any prescription or non-prescription medication
• Subject consumes excessive amounts of alcohol or caffeine
• Subject has had major surgery, donated blood or participated in another investigational study in the past 4 weeks